H-1 NMR proximal histidyl NdeltaH signals of deoxy hemoglobin (Hb) and
myoglobin (Mb) are distinguishable in the rat myocardium in situ. In
the normoxic resting state, the blood and tissue pO(2) is sufficient t
o saturate both Mb and Hb, No deoxy Mb or Hb signals are detected. Und
er 12% inspired O-2, the erythrocyte Hb is partially desaturated and y
ields the alpha and beta proximal histidyl NdeltaH signals of deoxy Hb
. The detection of the Hb signals clarifies the debate about the NMR v
isibility of erythrocyte Hb in vivo and augments the strategy to obser
ve tissue pO(2). (C) 1998 Federation of European Biochemical Societies
.